New materials of plesiacerathere (Perissodactyla, Rhinocerotidae) from the late Early Miocene of Northern China.

As a member of Aceratheriinae, the genus in Europe is widely distributed and highly diverse. However, only one species of (, ) exists in China with a discontinuous distribution range. Recently, we have discovered new materials of in the lower layers of the Zhang'enbao Formation exposed in Miaoerling in Tongxin County, China. The new materials are well-preserved and can be separated from other species by the following combination of features: the long and generally flat skull, with closed frontoparietal crests; the deep nasal notch at the level of P4; the high supraorbital margin, with its anterior margin at the level of the M1/M2 boundary; the medium-sized upper I1, with an oval abraded surface; the semi-molarized upper premolars with the protocone and hypocone joined by a lingual bridge; the strong constrictions of protocone on the upper molars; the absent buccal cingulum on upper cheek teeth; the cheek teeth are covered by cement on the buccal walls; the convex base of mandibular corpus; the inclined backward ramus; and the mandibular foramen above the teeth neck. Based on the combination of characteristics and phylogenetic analysis, we herein establish the new species as sp. nov. living in the late Early Miocene. Phylogenetic analysis reveals that is in the basal position of the genus , providing more detailed morphological characteristics of the plesiaceratheres.